A variety of multi-layer metal gaskets have been proposed for use as head gaskets. Such gaskets employ elastomeric coatings, sealing beads and a myriad of techniques to seek to generate effective seals around combustion openings and other openings requiring sealing.
In certain classes of such laminated gaskets, folded over flanges are used at combustion openings and embossments or beads are disposed under the flanges to assist in providing a seal threat. Known gaskets of this type tend to concentrate the applied loads in one annular zone, such as in the area of the folded over flange sometimes referred to as the "nose". This can result in extrusion of the microsealing layers, brinelling of a surface to be sealed thereby, and ultimately loss of the seal. Since there is no back-up to the seal at the nose area, the gasket can then fail.
It would be desirable to distribute the applied load in the zone of the flange so that there is an effective back-up seal, so that long term recovery will be provided in the flange area, and so that the tendency to brinell and the tendency of any rubber coatings to extrude could be minimized.